Problem: If $x \otimes y = (8-x)(y)$ and $x \oplus y = x^{2}-4y^{2}$, find $(4 \oplus -2) \otimes 3$.
Explanation: First, find $4 \oplus -2$ $ 4 \oplus -2 = 4^{2}-4(-2)^{2}$ $ \hphantom{4 \oplus -2} = 0$ Now, find $0 \otimes 3$ $ 0 \otimes 3 = (8-0)(3)$ $ \hphantom{0 \otimes 3} = 24$.